xbps-src: move helpers to environment; there's no need to have them.

Those helpers were just setting up some extra functions that can be used
on templates, and this can be done already via environment, so let's remove
the helpers completely.

common/environment/setup/replace-interpreter.sh

@@ -0,0 +1,41 @@
+# This helper replaces shebang paths pointing to the correct ones
+# as used by xbps. Multiple languages are supported:
+#
+#	- GNU Bash
+#	- Perl
+#	- Python
+#
+
+bash_regexp=".*sh"
+perl_regexp=".*perl[^[:space:]]*"
+python_regexp=".*python[^[:space:]]*"
+
+replace_interpreter() {
+	local lang="$1" file="$2" trsb orsb
+
+	[ -z $lang -o -z $file ] && return 1
+
+	case $lang in
+	bash)
+		orsb=$bash_regexp
+		trpath="/bin/bash"
+		;;
+	perl)
+		orsb=$perl_regexp
+		trpath="/usr/bin/perl"
+		;;
+	python)
+		orsb=$python_regexp
+		trpath="/usr/bin/python"
+		;;
+	*)
+		;;
+	esac
+
+	if [ -f $file ]; then
+		sed -i -e "1s|^#![[:space:]]*${orsb}|#!${trpath}|" $file
+		msg_normal "Transformed $lang script: ${file##$wrksrc}.\n"
+	else
+		msg_warn "Ignoring unexistent $lang script: ${file##$wrksrc}.\n"
+	fi
+}